Energy Selective Antenna: Concept, Design, and Experiment

In this article, a novel concept of energy selective antenna (ESA) is presented for integrating the functions of the common antenna and the adaptive high-power electromagnetic protection. To demonstrate this concept, a typical structure based on the microstrip patch antenna loaded with limiting PIN diodes is designed. It behaves as a normal antenna under the low-power incidence with the off -status of PIN diodes but rejects the signal in the interested frequency band when the PIN diodes are triggered by the high-power electromagnetic waves. An equivalent circuit is presented to illustrate the operation principle and the parametric studies are carried out to investigate the effects of several key factors on the proposed ESA. Furthermore, a prototype is fabricated and the measured results indicate that the antenna has excellent bandwidth and radiation performance in the normal working state, while performing a good isolation of more than 25 dB in the protection state.